Animals

Bioengineered obese mouse, Aberdeen, Scotland, 1998

The role of animals in medical discoveries

What do cows, dogs and fruit flies have in common? All of them played a crucial role in medical discoveries. Edward Jenner celebrated the cows who provided the first protection against smallpox by calling his new method ‘vaccination’ (from the Latin word vacca, for cow). The Russian physiologist Ivan Pavlov famously used dogs in his experiments on the relationship between sense stimulation and bodily functions. He showed that dogs could be conditioned to salivate when they heard a bell, which they associated with feeding. The American geneticist T H Morgan (1866-1945) used the fruit fly (Drosophila) for his observations of hereditary mechanisms. Fruit flies are well suited to such observations, because they breed very fast, they have big chromosomes that are easy to see, and they mutate frequently. With powerful microscopes Morgan could link changing genes to changing features of the body.

Antiquity to the 1600s: experimenting on animals

Animals have been used in dissections, experiments and medical treatment since Antiquity. Greek physicians such as Galen dissected pigs and monkeys to develop his knowledge of anatomy, but cautioned his colleagues that human bodies were very different from those of animals. In the 1600s, William Harvey experimented on animals to investigate the circulation of blood. The French scientist René Reaumur (1683-1757) trained a pet bird to swallow and regurgitate small pieces of food so that he could investigate the process of digestion.

From the 1800s to today: the increase in animal experimentation

Animal experiments became more frequent with the rise of experimental physiology in the 1800s. The French physiologist Claude Bernard, for instance, used animals in his work on digestion. Since 1900, animals have been central to the investigation of heredity and the new discipline of genetics. Other ‘model organisms’ of modern genetics include the fungus Neurospora, the mouse and the bacterium Escherichia coli. The celebrity sheep Dolly was the first successful result of cloning mammals. Today, scientists use purpose-bred animals such as the unfortunate obese mouse to investigate all sorts of bodily phenomena from obesity to ageing, and genetic diseases such as sickle-cell anaemia and thalassaemia.

Do animals feel pain? The change in belief from the 1700s

In the early modern period, many doctors saw nothing wrong with experimenting on animals. Philosophers such as René Descartes even claimed that animals did not feel pain. This attitude began to change in the 1700s. In 1758, Samuel Johnson criticised animal experimentation, claiming it would lead to a lack of compassion: ‘He surely buys his knowledge dear, who learns the use of the lacteals at the expense of his humanity.’

Animals and therapy

Animals contributed not only to medical experimentation, but also to medical therapy. In some cases, doctors make use of animals' natural behaviour. Leeches, for example, have long been employed in the practice of bleeding. (Today, medical scientists have reintroduced the ancient practice of using maggots to clean wounds.) Animals have also been used as raw material. Before the discovery of clotting factors, physicians attempted blood transfusions from animals to humans.

The 1876 British government response to testing on animals

In the 1800s, activists such as Frances Power Cobbe organised a strong protest movement against vivisection. In 1876 the British government responded to the anti-vivisectionists with the Cruelty to Animals Act, which regulated animal experimentation. The debate continues to the present day, since animals are still used in medical research. But some researchers are now able to find alternative methods, such as experiments on cell cultures or computer simulations.

J P Gaudillière, 'Making mice and other devices: the dynamics of instrumentation in American biomedical research (1930-1960)', in B Joerges, and T Shinn, T. (eds), Instrumentation: Between Science, State and Industry (Amsterdam: Kluwer, 2001), pp 175-196

H Kean, Animal Rights. Political and Social Change in Britain since 1800 (London: Reaktion Books, 1998)